From many, many posts on another website most of the steering head bearing failures were at the hands of the Triumph Factory, or a trained mechanic doing a scheduled service, so I wouldn't adjust it tho the factory specification.
The problem is the top bearing is used in an improper loading situation. A standard ball bearing is NOT designed for much side loading at all. When you adjust the races the top bearing is being side loaded in the Triumph setup. It is a standard radial ball bearing and not designed for this type of load. The lower bearing is a tapered roller bearing and is the one that does (and should) take the majority of the loads in their setup. The top bearing should only keep things centered and not be placed under much load (torque setting) at all.
Here's how I do them and I still have the original bearings in mine after 25k. Some people have gone through three or more sets during that time and were replaced by the dealer under warranty claims.
1. Get the front wheel off the ground. (An inch or two is fine) This way you can get some room to grease the lower tapered bearing which is not a sealed bearing. (it will be pretty dry!)
2. Remove the top triple tree. (Do not re-tighten the pinch bolts until all the adjustments have been finished). This will allow the wheel assembly to drop and give you access to grease the lower bearing.
3. Take out the top bearing (it's sealed) and make sure it doesn't have any rough spots. If it does replace it. They're only about $3.00! (unless you go to the dealer!) Part #6205-2RS
4. When you put it all back together only tighten the adjusting nut as much as you can WITH THE SOCKET HELD IN YOUR HAND! Do not use any tools here, just the bare socket and hand tighten it!
5. Rotate the handle bars back and forth to distribute the grease you applied to the lower bearing.
6. Loosen the adjusting nut and repeat step #4.
7. Be sure the assembly does not tighten (adjusting nut turns) when you tighten the top nut. Your done! And you're top bearing will not die because it was side loaded excessively. Don't forget to tighten the pinch bolts on the top triple tree now.
Now, there are a couple of fixes for this as well. They both require the replacement of the top bearing which is being used incorrectly unless it is not put under any side load, which is virtually impossible.
Replace the top bearing with an ANNULAR CONTACT bearing which is designed for radial as well as side loading. They can be had for about $12.00 and are a complete drop in replacement. Part #7205 Annular contact bearings.
Or replace the top bearing with another tapered roller bearing. These are also a drop in replacement except they are just under 1/16" to wide which really shouldn't bother anything. The top triple tree needs to be removed anyway and readjusted for bearing replacement or if you're just doing a bearing check. Part #30205 Tapered roller bearing. About $10.00 each.
The tapered roller bearing will take more side loading, but the Annular will be more than enough here. Either one will be fine.
Stock Replacement Bearing
Annular Contact Bearing
Tapered Roller Bearing
A little tip I used in using these bearings in not so clean environments such as this sense both the Annular and Tapered bearings are not sealed. Find an 'O' ring that will just lay around the inner race and cover the area where the rollers and grease would get dirt in them. Get the 'O' ring thick enough to just be compressed slightly when assembled in the assembly. This will keep out 95% of the dirt and keep the grease in the bearing as well.
[ This message was edited by: Stlakid on 2006-10-10 03:21 ]
The problem is the top bearing is used in an improper loading situation. A standard ball bearing is NOT designed for much side loading at all. When you adjust the races the top bearing is being side loaded in the Triumph setup. It is a standard radial ball bearing and not designed for this type of load. The lower bearing is a tapered roller bearing and is the one that does (and should) take the majority of the loads in their setup. The top bearing should only keep things centered and not be placed under much load (torque setting) at all.
Here's how I do them and I still have the original bearings in mine after 25k. Some people have gone through three or more sets during that time and were replaced by the dealer under warranty claims.
1. Get the front wheel off the ground. (An inch or two is fine) This way you can get some room to grease the lower tapered bearing which is not a sealed bearing. (it will be pretty dry!)
2. Remove the top triple tree. (Do not re-tighten the pinch bolts until all the adjustments have been finished). This will allow the wheel assembly to drop and give you access to grease the lower bearing.
3. Take out the top bearing (it's sealed) and make sure it doesn't have any rough spots. If it does replace it. They're only about $3.00! (unless you go to the dealer!) Part #6205-2RS
4. When you put it all back together only tighten the adjusting nut as much as you can WITH THE SOCKET HELD IN YOUR HAND! Do not use any tools here, just the bare socket and hand tighten it!
5. Rotate the handle bars back and forth to distribute the grease you applied to the lower bearing.
6. Loosen the adjusting nut and repeat step #4.
7. Be sure the assembly does not tighten (adjusting nut turns) when you tighten the top nut. Your done! And you're top bearing will not die because it was side loaded excessively. Don't forget to tighten the pinch bolts on the top triple tree now.
Now, there are a couple of fixes for this as well. They both require the replacement of the top bearing which is being used incorrectly unless it is not put under any side load, which is virtually impossible.
Replace the top bearing with an ANNULAR CONTACT bearing which is designed for radial as well as side loading. They can be had for about $12.00 and are a complete drop in replacement. Part #7205 Annular contact bearings.
Or replace the top bearing with another tapered roller bearing. These are also a drop in replacement except they are just under 1/16" to wide which really shouldn't bother anything. The top triple tree needs to be removed anyway and readjusted for bearing replacement or if you're just doing a bearing check. Part #30205 Tapered roller bearing. About $10.00 each.
The tapered roller bearing will take more side loading, but the Annular will be more than enough here. Either one will be fine.
Stock Replacement Bearing
Annular Contact Bearing
Tapered Roller Bearing
A little tip I used in using these bearings in not so clean environments such as this sense both the Annular and Tapered bearings are not sealed. Find an 'O' ring that will just lay around the inner race and cover the area where the rollers and grease would get dirt in them. Get the 'O' ring thick enough to just be compressed slightly when assembled in the assembly. This will keep out 95% of the dirt and keep the grease in the bearing as well.
[ This message was edited by: Stlakid on 2006-10-10 03:21 ]